Tesco said: “We have been made aware that some Tesco butters may potentially have low levels of Listeria monocytogenes present.

“As a precautionary measure, we are recalling affected products from customers.”

The complimentary butter discs are “offered to customers at the fresh meat and fish counters. Customers are advised to discard them.

“Please do not consume these products.

“Please return the affected products to store where a full refund will be given. No receipt is required.

“Tesco apologises to our customers for any inconvenience caused.”

The Food Standards Agency said: “Tesco has taken the precautionary step of recalling some flavoured butter products due to the possible presence of Listeria monocytogenes.

“Listeria monocytogenes is a bacterium that can cause foodborne illness, particularly among key vulnerable groups, including pregnant women, unborn and newborn babies, those over 60 years old, and anyone with reduced immunity.

“No other Tesco products are known to be affected.

“Tesco has taken the precautionary measure of recalling all products that may be affected. Tesco has published a point-of-sale notice which is attached to this notice.

“Consumers are advised not to consume any of the above products, and return the affected products to store where a full refund will be given.”